A&a Manuscript No. Astronomy and Astrophysics Dense Gas in Nearby Galaxies Xiv. Detection of Hot Ammonia in Maaei 2

version lines of ammonia (NH 3) have been detected toward the nuclear 40 00 sized bar of the nearby spiral galaxy Maaei 2. The relative intensities of the ammonia lines are characterized by a rotational temperature of 85 K. This is higher than rotational temperatures measured toward IC 342 and most Galactic Center clouds, implying kinetic temperatures > 100 K. Since the kinetic temperature of the gas is larger than that of the dust, NH 3 is tracing a particularly dense warm gas component that is heated by young massive stars, cloud-cloud collisions, or ion-slip heating in the nuclear starburst. The gas north of the nucleus (V LSR = {80 km s ?1) is more highly excited than the gas further south (+6 km s ?1). This asymmetry might be related to pronounced morphological distortions that are observed in the northeastern part of the galaxy.